That depends whether you celebrate Pi day on 3.14 (March 14) or 22/7 (July 22).
The day of the week was a Saturday.
22 June 1975 was a Sunday.
25 October 1975 was a Saturday.
January 22 1975 was a Wednesday.
17 September 1975 was a Wednesday.
21 February 1975 was a Friday.
28 February 1975 was a Friday.
3 December 1975 was a Wednesday.
22 October 1975 was a Wednesday.
25 July 1975 was a Friday.
June 13, 1975 was a Friday.
February 13 1975 was on a Thursday.